In recent years, a configuration of a network that controls a Machine Type Communication (MTC) terminal that autonomously performs communication without requiring operations by a user or the like has been discussed. For example, a Device Trigger function, which performs communication with the MTC terminal, has been discussed in the 3GPP, which promotes standardizations regarding configurations and functions of mobile networks. The Device Trigger function is a function that is used when a server apparatus (hereinafter it will be referred to as an external server apparatus) that belongs to a network different from the mobile network performs communication with the MTC terminal which belongs to the mobile network. The MTC terminal may also be called a Machine to Machine (M2M) device. For example, Patent Literature 1 discloses a configuration and a flow of processing for executing the Device Trigger function.
In the Device Trigger function, for example, the external server apparatus specifies an MSISDN (it corresponds to the telephone number) allocated to the MTC terminal, and further transmits a small amount of data using a short message service (SMS) to the MTC terminal device. The small amount of data is, for example, data in which the upper limit is predetermined in the SMS and the number of characters that can be sent is limited to tens of characters.
However, the MTC terminal is supposed to be incorporated into non-communication devices, machines or the like other than mobile telephones or smartphone terminals, and it is supposed that the number of MTC terminals incorporated into the non-communication devices or the machines will reach from tens of millions to hundreds of millions. Therefore, if the MSISND is allocated to all the MTC terminals, the MSISDN may be depleted. It has therefore been discussed to allocate, by a communication carrier or the like of the mobile network, an External Identification (External-ID) having a number of digits greater than that of the MSISDN to the MTC terminal and to specify, by the external server apparatus, the External-ID and perform communication with the MTC terminal.